The present application relates to a semiconductor structure and a method of forming the same. More particularly, the present application relates to a lateral bipolar junction transistor (BJT) having increased collector current drive and current gain which is formed utilizing a replacement gate processing flow.
A bipolar junction transistor (BJT) is a semiconductor device containing an emitter region, a base region and a collector region having two P-N junctions with one of the P-N junctions being located between the emitter region and the base region, and the other P-N junction being located between the collector region and the base region. Each BJT can thus be classified as either PNP or NPN according to the arrangement of the p-type semiconductor material and the n-type semiconductor material. An NPN BJT has an n-type emitter region, a p-type base region, and an n-type collector region. A PNP BJT has a p-type emitter region, an n-type base region, and a p-type collector region. The function of a BJT is to amplify current, i.e., the collector current output (output signal) is larger than the base current (input signal).
One type of BJT is a lateral BJT. In a lateral BJT, the base region is located between the emitter region and collector region, with the emitter/base junction and the collector/base junction being formed between laterally arranged components. Lateral BJTs have drawn significant attention over the past decade due to their ease of processing and compatibility with mainstream complementary metal oxide semiconductors (CMOS). Lateral BJTs are suitable for digital as well as analog/mixed-signal applications. High-performance lateral BJTs that have increased collector current drive and current gain are needed to improve circuit speed.